This invention relates to a process for extracting from coal a material which is especially effective as a gasoline additive, to the extracted material, and to gasoline additive compositons and fuel compositons prepared therewith. In particular, the present invention provides a gasoline additive which effectively increases the duration of motor operation obtainable with a given amount of fuel.
Many processes using many solvents have been proposed for the solvent extraction of coal and uses for the extract or its conversion to valuable hydrocarbons, usually by hydrogenation, described. For example, U.S. Pat. No. 1,822,349 teaches many solvents for coal extraction; U.S. Pat. No. 2,141,615 teaches the use of solid coal extracts as powdered fuel in combustion engines; U.S. Pat. No. 2,215,190 teaches hydrogenating coal extract to produce gasoline, diesel oil, lubricating oil, and the like. The complex composition of coal and the complexity of extracts thereof are also well recognized (U.S. Pat. Nos. 3,379,636, 3,162,594 and 3,018,241, for example). A summary and discussion of the solvent extraction of coal is provided by Chemistry of Coal Utilization, Supplementary Volume, H. H. Lowry, Editor, published by John Wiley & Sons, Inc. (1963), especially pages 237 through 252; certain uses for coal extracts are discussed on page 250, and the remarkably few commercial applications are indicated on page 252.